Rigid arm mooring means



May 6, 1969 J, A` CHRISTlANS ET AL 3,442,245

RIGID ARM MOORING MEANS Filed April 8, 1968 /C/G. f

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United States Patent O U.S. Cl. 114--230 5 'Claims ABSTRACT F THE DISCLOSURE This invention relates to a single buoy mooring system (SBM) and, more particularly, to a monomooring means wherein the structure that rigidly moors a tanker also provides for the delivery of iluids between the tanker and a land based source or storage facility. The rigid arm mooring means of this invention can be made up of four rigid iluid transporting pipes which are pivoted end to end in the form of a rectangle. One such pivot is connected to a mooring buoy and is capable of pivoting therearound. The diagonally opposite pivot is connected to a saddle which is secured to a tanker. The remaining pivots are mounted on fender buoys and are limited in their separation by nylon ropes. The distance between the tanker and the mooring buoy is limited by the length of mooring ropes. When loading onto a tanker, the fluid passes through a submarine pipeline into a swivel mounted centrally on a buoy on through the rigid pipes and the pivots to the saddle where a flexible pipe delivers lluid to the tanker manifold, usually at midship.

The invention described herein may be manufactured and used by or for the Government `of the United States of America for governmental purposes without the payment to us of any royalties thereon.

Field of the invention This invention is in the class of mooring buoy for floating vessels whereby fluids are passed through the mooring means.V

Description of the prior art In the art of monomooring, there is a need for a rigid mooring device which Will prevent the moored vessel from damaging the buoy and floating hoses. No prior art is known to solve these problems in the manner set forth in this application.

Summary The invention of this disclosure is a device for mooring tankers of any size for loading or discharging fluids. A

tanker is maneuvered into a saddle `which is pivoted onto the rectangular rigid pipes. Mo'oring ropes are connected from a mooring buoy to a forward mooring point on the tanker. The maximum distance between the mooring buoy and the tanker is determined by the length of these mooring ropes. Four rigid pipes, or metal frames, are pivoted at each end to form a rectangle with one pivot being at the saddle, one pivot being at the mooring buoy, and the other two pivots being on fender buoys which make up the other two opposite corners of a rectangle. The combined length of the two pipes pivoted at the saddle is greater than the length of nylon ropes which are connected between the two pivots on the fender buoys. The combined length of the rigid pipes pivoted on the mooring buoy is also longer than the nylon ropes connecting the pivots on the fender buoys.

This device is added to a single buoy mooring system (SBM) to overcome some of the operation problems now being encountered. The present SBM consists of a moor ing buoy secured in place by a plurality of anchors and anchor chains. The ship is secured to the buoy by means of mooring lines, such as nylon rope, for example. The liquid cargo from ship to shore or from shore to ship travels, in the case of olf loading, from the tanker manifold into flexible pipes, such as rubber hoses, to oating hoses, to the pipes at the buoy, into a swivel mounted centrally on the buoy, through the submarine or under buoy hoses, into the submarine pipe lines and on to shore. With such prior device, in calm weather the ship will ride up on the buoy and endanger it as well as the iloating hoses. Further, during rotation of the ship around the buoy, such as occurs when tide current changes direction, the ship often strikes the buoy as well as damages the floating hoses. Another difculty encountered in the prior device occurs during periods of high loading. The ship can surge in a forward direction because of lack of restraint causing sharp increases in mooring forces.

The rigid arm mooring means of this invention will greatly reduce the above said problems or eliminate some of them completely. Further, this invention permits replacement of the expensive floating hose by cheaper, wider diameter steel pipe. This has the bonus ot reducing the amount of pressure loss while permitting higher flow rates.

These advantages result in a monomooring system that is not only free of the troubles of damaged buoys, cables and pipelines, but is capable of better flow of liquid to and from the vessel.

It is, therefore, an object of this invention to provide a monomooring system which makes use of a tension member connected across a diagonal of rigid rectangular structure to limit the approach of a vessel to a mooring buoy.

Another object of this invention is to provide a monomooring system which is constructed in such a manner as to prevent damage of the iiuid carrying lines by any movement of the vessel while it is moored at the buoy.

Still another object of this invention is to provide a monomooring system which utilized less expensive fluid handling materials to provide more efficient delivery of uids to and from a vessel.

The exact nature of this invention as well as other objects and advantages thereof will be readily apparent from consideration of the following specification relating to the annexed drawings in which:

Brief description of the drawings FIGURE l shows the monomooring system from above, and

FIGURE 2 shows the monomooring system in plan view.

Description of a preferred embodiment Turning now to the drawings, a monomooring buoy 10 is anchored by cables or chains 9 connected to embedded anchors or dead weights not shown. A vessel 11, such asa tanker, is connected to buoy 1t) through a structure made up of pivot means 12 on buoy 10 to which are connected pipe or frame members 13 and 14. Two other pipe or frame members 17 and 18 are provided. Pipe 17 is connected to pipe 13 by a pivot means 15 and pipe 18 is connected to pipe '14 by a pivot means 16. Pipes 17 and 18 are connected to each other by pivot means 19. Pivot means 15 and 16 are each mounted on one of a pair of fender buoys 8 which not only support. the pipes but provide for limiting the amount that the vessel 11 pivots about pivot 19.

Connected to pivots 15 and 16 across a diagonal of the rectangular structure formed -by the four pipes are rope means, such as nylon rope, to prevent the buoys 8 from separating far enough to permit pivot 19 to apa proach the buoy 10. Mooring lines 23 and 24 are connected from buoy lltl to cable securing means 31 and 32, respectively, aboard the vessel 11 to limit the distance that the vessel 11 can move away from buoy 1t? while being moored thereto.

Pivot 19 can be a universal joint connected to a saddle 25 which surrounds the bow of the vessel to assure the correct positioning of the vessel with respect to the pviot 19. The saddle 26 is secured to the vessel by lines connected to cable securing means 28 and 29 on the deck of the vessel.

FIGURE 2 shows the arrangement of the pipes 13, 14, 17 and 18 so that fluids such as fuel or lubricants, can flow through submerged line 6 from a shore installation through buoy 10, pivot 12, and through either pipe 13, pivot 15, pipe 17 or arm 14, pivot 16, arm 18 to pivot 19 and out pipeline 7 which goes back to the manifold on the vessel. It is understood that pipeline 6 could extend through either fender buoy 8 instead of through mooring buoy 10. In cases where rigid frames are used instead of pipes, a exible pipe can -be secured to the frame to accomplish the same purpose as using pipes. Obviously, the fluid would be equally readily transmitted from the manifold to the shore installation.

The flow system is through one side of the rectangular frame from the mooring buoy to emerge at the saddle into a oating or submerged steel pipe which runs backward to the area of the manifold. Rubber or other flexible hose is then used to connect the steel pipe to the manin fold.

When the tanker is connected into the saddle, a set of Wire ropes 26 and 27 is connected from the saddle to securing points a substantial distance rearward aboard the tanker. As the tanker rises or settles in response to being emptied or filled, respectively, the saddle remains at one level with respect to the water surface and ropes 26 and 27 maintain the tanker secured thereto.

The rectangular rigid pipe structure is free to move and follow the tanker away from the buoy until such rearward motion is stopped by the mooring ropes secured to the buoy. The top of buoy 10 to which ropes 23 and 24 are connected rotates with the pipe structure. Should the tanker move toward the buoy, the nylon ropes connecting the two pivots on the fender buoys are loaded sufficiently to limit the movement toward the buoy. This is because the ropes 21 and 22 are diagonal tension braces for a rectangular structure. The lengh of the nylon ropes determines the closeness that the tanker approaches the buoy.

The tanker may also pivot with the saddle until a side of the tanker is against one of the fender buoys. At this point the rectangular structure of pipes will rotate about the mooring buoy to protect the buoy and hoses. A fourth buol can be connected under saddle 19 to give support thereto.

The flow system of this invention is along one rigid pipe and enters a hose that enters the water at the end of the saddle at one end through the bottom of a fender buoy at the other end. Alternately, two pipes, such as 14 and 18 can be utilized for the flow to be through both of them to enter the hoses 6 and 7 beneath the mooring buoy 10 and the saddle pivot 19, respectively. It is seen that the ship can never damage the hoses nor the mooring buoy. The ow system from either end of the rigid pipe means can be through flexible Ahoses or through a submerged steel pipe and fioating hose combination.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood, that the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. In a mooring system:

a mooring buoy;

a first, second, third and fourth rigid means, each having alfirst and a second end;

a rst, second, third and fourth pivot means;

a first and a second fender buoy;

a saddle means having means for connecting to said fourth pivot means and means for connecting to a vessel;

said first pivot means mounted on said mooring buoy;

said rst ends of said first and second rigid means connected to said first pivot means;

said rst ends of said third and fourth rigid means and said saddle means connected to said fourth pivot means;

said second ends of said first and third rigid means connected to said second pivot means on said first fender buoy;

said second ends of said second and fourth rigid means connected to said third pivot means on said second fender buoy;

tensioning means connected between said first and second fender buoys of shorter length than the combined length of said second and fourth rigid means;

and mooring lines one end of each is connected to said mooring buoy and the other end of each is available to be connected to a vessel.

2. The mooring system of claim 1:

and means for forming a fuel passage means 'through said fourth rigid means.

3. The mooring system of claim 1:

and means for forming a continuous fuel passage means through said mooring buoy, said second rigid means, said third pivot means, said fourth rigid means, and said fourth pivot means.

4. The mooring system of claim 1:

and means for forming a continuous fuel passage means through said mooring buoy, said first rigid means, said second pivot means, said third rigid means and said fourth pivot means.

5. In the mooring system of claim 1:

said tensioning means comrising nylon ropes.

References Cited UNITED STATES PATENTS 3,155,069 11/1964 Ross et al 114-230 3,354,479 11/1967 Koppenol et al.

TRYGVE M. BLIX, Primary Examiner.

Us. c1. Xn, 9 8 

